SMILE (spacecraft)

The mission will observe the [[solar wind]] interaction with the [[magnetosphere]] with its X-ray and ultraviolet cameras (SXI and UVI), gathering simultaneous images and videos of the dayside [[magnetopause]] (where Earth's magnetosphere meets the solar wind), the polar cusps (a region in each hemisphere where particles from the solar wind have direct access to Earth's ionosphere), and the auroral oval (the region around each geomagnetic pole where auroras most often occur). SMILE will also gather simultaneously in situ measurements with its two other instruments making up its payload – an ion analyser (LIA) and a magnetometer (MAG). These instruments will monitor the ions in the [[solar wind]], [[magnetosheath]] and [[magnetosphere]] while detecting changes in the local DC magnetic field.{{Citation needed|date=February 2026}}

The mission will observe the [[solar wind]] interaction with the [[magnetosphere]] with its X-ray and ultraviolet cameras (SXI and UVI), gathering simultaneous images and videos of the dayside [[magnetopause]] (where Earth's magnetosphere meets the solar wind), the polar cusps (a region in each hemisphere where particles from the solar wind have direct access to Earth's ionosphere), and the auroral oval (the region around each geomagnetic pole where auroras most often occur). SMILE will also gather simultaneously in situ measurements with its two other instruments making up its payload – an ion analyser (LIA) and a magnetometer (MAG). These instruments will monitor the ions in the [[solar wind]], [[magnetosheath]] and [[magnetosphere]] while detecting changes in the local DC magnetic field.{{Citation needed|date=February 2026}}

SMILE must reach a high enough altitude to view the outside edge of Earth's magnetopause and at the same time obtain good spatial resolution of the auroral oval. The chosen orbit is therefore highly elliptical and highly inclined (73 degrees depending on the launcher), and takes SMILE a third of the way to the Moon at apogee (an altitude of 121 182 km, i.e. 19 Earth radii or R_E).{{Citation needed|date=February 2026}}

SMILE must reach a high enough altitude to view the outside edge of Earth's magnetopause and at the same time obtain good spatial resolution of the auroral oval. The chosen orbit is therefore highly elliptical and highly inclined (73 degrees), and takes SMILE a third of the way to the Moon at apogee (an altitude of 121 182 km, i.e. 19 Earth radii or R_E).{{Citation needed|date=February 2026}}

[[File:Smile spacecraft is complete for the first time ESA506849.jpg|thumb|On 21 January 2025, engineers at ESA connected the two main parts of the Smile spacecraft, putting it into its final flight configuration.|450x450px]]

[[File:Smile spacecraft is complete for the first time ESA506849.jpg|thumb|On 21 January 2025, engineers at ESA connected the two main parts of the Smile spacecraft, putting it into its final flight configuration.|450x450px]]